Embedding climate change risk into mine closure planning: a case study of tailings closure design at Ballarat Gold Mine

Authors: Trotta, LM; Ridgway, TH Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2215_15

Cite As:
Trotta, LM & Ridgway, TH 2022, 'Embedding climate change risk into mine closure planning: a case study of tailings closure design at Ballarat Gold Mine', in AB Fourie, M Tibbett & G Boggs (eds), Mine Closure 2022: Proceedings of the 15th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 259-266, https://doi.org/10.36487/ACG_repo/2215_15



Abstract:
It is commonly accepted that climate change is a global challenge requiring a strong response led by both government and business. Rising levels of atmospheric greenhouse gases are increasing the severity and occurrence of extreme weather events such as storms and heatwaves and are accelerating rising sea levels. This changing climate will affect the infrastructure and resources sector both directly and indirectly. By building operational climate resilience today, companies can limit future liabilities, support business continuity, and improve the sustainability of communities and ecosystems. With an increased focus on closure planning and design within the resources industry, especially in tailings management, it is important to establish a clear set of expectations early in the planning phase. Closure planning provides mines and smelters an opportunity to evaluate climate projections under different emission scenarios, identify and assess potential future climate hazards and associated risks, and modify final landform design to accommodate the identified physical climate risks. In several countries, nominally Australia, Canada and Chile, long-term assessment of tailings closure landforms is considered essential within the industry. For such assessments to be effective, long-term climate change data projections are required. By undertaking such assessments early, the closure design team can accommodate both current and forward hydrological projections as well as long-term behavioural changes of the capping material, with respect to potential changes in climate conditions such as increased temperatures and extended solar exposure. This process has recently been successfully implemented at Ballarat Gold Mine as part of the closure and rehabilitation planning process. The results of these assessments, while being used in the design and forward planning of the closure of the tailings storage facility (TSF), have also been incorporated into the site-wide risk assessment and risk management plan. This paper outlines the climate change risk assessment process undertaken for the Ballarat Gold Mine TSF, specifically the considerations, procedures and outcomes of the assessment. It furthermore describes how these prompted a re-evaluation of the final TSF design to enable it to withstand projected extreme climate events.

Keywords: climate change risk, climate resilience, tailings closure design, final landform design, Ballarat Gold Mine

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